Five-leaved Clover 365 



succession of the periods of life, is evidently of 

 no consequence, and in this way the law of 

 periodicity may be regarded as a special in- 

 stance of the more general law of response to 

 external conditions. 



The validity of this law of periodicity is of 

 course not limited to our ^^ five-leaved " clover. 

 Quite on the contrary it is universal in ever- 

 sporting varieties. Moreover it may be ascer- 

 tained and studied in connection with the most 

 widely different morphologic abnormalities, and 

 therefore affords easily accessible material for 

 statistical inquiry. I will now give some fur- 

 ther instances, but wish to insist first upon the 

 necessity of an inquiry on a far larger scale, 

 as the evidence as yet is very scanty. 



The great celandine (Chelidonium ma jus) 

 has a very curious double variety. Its flowers 

 are simpler and much more variable than in 

 ordinary garden-varieties. The process of 

 doubling consists mainly in a change of stamens 

 into petals. This change is dependent on the 

 season. On each stem the earliest flowers are 

 single. These are succeeded by blossoms with 

 one or two converted stamens, and towards the 

 summer this number increases gradually, attain- 

 ing 10 - 11 and in some instances even more 

 altered filaments. Each vear the same succes- 

 sion may be seen repeating itself on the stems of 



